Common mistakes with AS 1940 Compliance
AS 1940:2017 covers the storage and handling of flammable and combustible liquids, including diesel and many oils (depending on their classification and flash point).
In Queensland, compliance is primarily driven by the Work Health and Safety Regulation 2011 (Qld) and the Hazardous Chemicals Code of Practice. While AS 1940 is not explicitly mandated in all circumstances, it is widely adopted as the accepted benchmark and is often required by Environmental Authorities, internal standards, Environmental Management Plans, and site procedures.
In addition, Section 357 of the WHS Regulation 2011 (Qld) requires that where there is a risk of a spill or leak of a hazardous chemical, appropriate spill containment must be provided.
AS 1940 is a detailed standard, and full compliance on operational sites can be challenging. However, there are several recurring issues that are frequently overlooked.
1. Portable bunding is not suitable for permanent storage
Portable bunding units such as bunded pallets and flexible bunds are commonly used across construction and operational sites.
However, these are not intended for permanent storage applications. AS 1940 makes it clear that portable bunding units are not suitable as a long-term bunding solution.
If containers are stored in a fixed location on an ongoing basis, a compliant permanent bunded area should be provided.
2. Bund capacity – 110% vs 100% + 25% (commonly misunderstood)
Bunding requirements under AS 1940 depend on the type of storage:
- Bulk tanks: bund capacity should be at least 110% of the largest tank
- Package storage (drums, IBCs): bund capacity should be at least:
- 100% of the largest container, plus
- 25% of the total stored volume
A common compliance issue is applying the 110% rule to IBCs or drum storage, which can significantly underestimate the required bund capacity.
Importantly, bunding requirements are based on container capacity, not the current volume stored. Nominally empty containers should still be considered from a capacity perspective unless they have been cleaned and decommissioned.
3. Rainwater reduces effective bund capacity
Bunds must maintain their required effective containment capacity at all times. Where bunds are not protected from rainfall, accumulated stormwater reduces available containment volume, which can result in non-compliance during a spill event.
Rainwater in bunds must be appropriately managed, including:
- controlled drainage via treatment (e.g. oily water separator), or
- removal and disposal to a suitably licenced facility (testing may be required), or
- testing prior to release (where appropriate)
Uncontrolled discharge of bund water to ground is a common compliance issue.
4. Undersized bunds for IBC storage
A frequently observed issue is an IBC stored on a small bund (e.g. 30cm deep shallow bund), often uncovered.
In many cases, these setups:
- do not meet the 100% + 25% capacity requirement, and
- are subject to rainwater infiltration (being uncovered)
These arrangements are rarely compliant when assessed against AS 1940.
5. Other common site issues (not limited to AS 1940)
While not strictly AS 1940 requirements, the following are also key risk areas in fuel and oil management:
- Missing or open bungs in oily waste bins
- Inappropriate detergents used in washdown areas (non quick-break)
- Oily water separators not operating or maintained correctly
Final note
Most sites have some form of bunding in place, but the detail of how it is designed, used, and maintained is where compliance gaps typically arise.
Understanding the difference between tank and package storage requirements, and ensuring bunds maintain their effective capacity in service, will address a large proportion of common issues.
Reach out if we can assist you in improving your management of flammable and combustible liquids.



